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Piyush K-----------------------Our greatest weakness lies in giving up. The most certain way to succeed is to try just one more time. ― Thomas A. EdisonDon't forget to press--> KudosMy Articles: 1. WOULD: when to use?| 2. All GMATPrep RCs (New)Tip: Before exam a week earlier don't forget to exhaust all gmatprep problems specially for "sentence correction".

The game will end after the fourth throw means that the fourth throw should be the last in the game.

Then sentence should be: what is the probability that the game will end with 4th throw? what is the probability that the game will end at fourth throw?

After 4th throw is ambiguous; I discussed this question with other people and they also inferred it same as I did.
_________________

Piyush K-----------------------Our greatest weakness lies in giving up. The most certain way to succeed is to try just one more time. ― Thomas A. EdisonDon't forget to press--> KudosMy Articles: 1. WOULD: when to use?| 2. All GMATPrep RCs (New)Tip: Before exam a week earlier don't forget to exhaust all gmatprep problems specially for "sentence correction".

The game will end after the fourth throw means that the fourth throw should be the last in the game.

Then sentence should be: what is the probability that the game will end with 4th throw? what is the probability that the game will end at fourth throw?

After 4th throw is ambiguous; I discussed this question with other people and they also inferred it same as I did.

Than you, Edited as you've suggested:

If a coin is tossed until the sequence \(HTH\) appears (\(H\) denotes the fall of heads, \(T\) denotes the fall of tails), what is the probability that the game will end with 4th throw?_________________

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14 Jul 2016, 01:08

I think this is a high-quality question and the explanation isn't clear enough, please elaborate. Though the answer is correct, I am wary of the explanation provided. In the solution, we are provided that there are 2 possible outcomes- THTH and HHTH out of the possible 16 outcomes. However, these 16 possible outcomes also include the cases HTHH and HTHT, which are not possible because the game would have ended with 3rd toss.

Shouldn't the solution be: [Probability that the game does not end with 3rd throw (7/8)] X [Probability that the game ends with 4th throw (2/14)]= 1/8